Manufacture of catalysts



J. BOYCE. MANUFACTURE OF CATALYSTS.

APPLICATION FILED JUNE 2, 19I3.

Patented May 11; 1920.

INVENTOR ya I ATTORNEYS.

IUNITEI) STATES, PATENT OFFICE.

JAMES BOYCE, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE AMERICAN COTTON OILCOMPANY, OF GUTTENBERG, NEW JERSEY, A CORPORATION OF NEW JERSEY.

MANUFACTURE/OF cA'rALYs'rs.

Specification 01' Letters Patent.

Patented May 11, 1920.-

Application filed June 2, 1913. Serial No. 771,325.

full, clear, and exact description of the in? ve'ntion, such as willenable others skilled in the art to which it appertainsto make and usethe same.

My invention relates to certain new and useful improvements in theproduction of contact bodies or catalysts designed particularly foremployment in the hydrogenation of unsaturated fats and the like, butcapable of" general employment in similar operations, involvingcatalytic or contact action.

In these operations, it is important that the catalyst should present alarge extent of surface for the total weight of metal employed, or,otherwise stated, that the minimum quantity of metal should be employedfor obtaining the extent of contact surface desired. I i

In practice, I find that by the use of 'catalysts produced in accordancewith my invention, I have been able to obtain, in the hydrogenation offats and the like, a quicker" result and a better product, producedlata' lower temperature as compared with operations wherein the catalystemployed is a powdered metal, as, for instance, powdered nickel.

My invention involves, as one of its mainpulverulent carrier, such aspumice stone.

These finely divided individual grains of inert material take the placeof the main body portion of the particles of powdered metal usuallyemployedfor may be considered as, individualwores upon which areuniformly spreadsuperficialj coatings presenting a much larger contactsurface than the same weight of metal in the pulverized J condition.vConsequently, the superficialdeposits upon'the minute particles q'fpumice stone very largely increase the activity of the" catalyst for*the weight of metal em: ployed, and nevertheless leave the catalyst inthe form of minute-particles capable of being mechanically stirred intothe liquid mass whose hydrogenation is to be effected,

'so as to present thereto constantly changing contact surfaces.

In the production of catalysts, in 'accordance with my invention, themetal, as willhereinafter more fully appear, is reduced from the oxid.Thus, the oxid of nickel is reduced by means of hydrogen gas, preferablyobtained, in a state of great purity, from the electrolysis of distilledwater, and

I have discovered, that in applying the hy-' drogen gas to the nickeloxid a very effective and superior catalyst isproduced by stopping thereduction of the oxid before such reduction is quantitatively complete.

fact, in practising my invention, I aim to The practice, the reducingaction of the hydro- 9 gen upon the nickel oxid is interrupted at astage before the disappearance of watery vapors in the issuing currentof hydrogen,

and the period at which the said interruption takes'place is so chosenthat the product shall be black or preponderatingly black in color. Theinterruption of the reduction can be brought about either by cutting offthe supply of hydrogen gas, or, preferably, by reducing the temperaturebelow that necessary for reaction. I have found that the blacker thecolor of the nickel black, the greater is its activity and the longerits life as a catalyst,-particularly in the hydrogenation of oil; forwhich reason, a relatively small amount of the nickel black is'efiective in thelhydrogenation of a given quantity of oil, and that itis highly effective at low temperatures,

that is 'to say, below the temperature of for.-

mation of the fatty acids, for which reason ft is especially adapted tothe hydrogenation of edible oils and fats.

- its oxid may .be'efiected;

In the accompanying. drawi I Figure 1 represents, in longltudinal'section, a suitable reduction tube whereinthat part of my inventionwhich relates specifically to the reduction of the catalyst from Fig. 2represents the longitudinal section of a furnace. structure appropriate.for the heating of reaction tubes of thischaractert and 4 I F ig."3represents atop plan view thereof. Similar letters of reference indicate'similar parts throughout the several views.

In carrying ou'tmy invention prefer to proceed from commercial metallic@nickel as a "starting point. -I treat. it in. an earthenware j arorlike receptacle with at least the theoretical quantity of nitric acidand water to produce, when hot, a solution of nitrate of nickel," andwhich, if permitted to cool would take onthe form ofla solidcrystallized nitrate of nickel, the heat of combina: tion sufiicing, inthat event, to drive off the water present. Instead of using exactly thetheoretical quantity of nitric acid, in making the nitrate, I on theacid side, t at is to say, I prefer to use a slight excess of nitricacid for a pur- I pose hereinafter to be. described. a

The supersaturated solution .of nitrate of nickel is not permittedtecool, but is added while still hot, to the pumice stone powdere to sa80 mesh, which is't'o serve as the carrier or the metal, and which isemployed'in the proportion of a proximately one part by volume; of powered pumice stone to three parts by volume of the hot solution.

The advantage, just indicated, of emplo aislight excess -of acid inmakin t e in 'sohition of-nickel nitrate iathat it is ound to actsuperficiallyupon the. surface'of the individual particles of pumicestone,, thereb"- minutely indentin 'or recessing the in- I dividualparticles an giving them a larger coast-'line ,or peripheral area uponWhlC -to receive the-nitrate of nickel. deposit. It

I is found in practice that in the hot state, the

"nickel nitrate immediatel adheres in crys-v "tallized form to; theminute 5 particles of pumie andthere is no necessity, therefore,"ofdrivmg 01! any excess of water P s, in order to obtain such adhesion.

. .clhe particlesof pumice-with their super a q ficlill' coating ofnickel nitrate. are. then" spread out in a'flat pan to a depth o'fwfromone to three'inches and 'thepanis thereupon gently heated," whereby thenickel 'ni'- 'trate is changed intoi ni ckeloxid'. It isof v particularim rtance that the niaterial'be subjected to e i g tively "shallowlayerindicated." If the layer-is too deep, it is found that it becomesj'so hard at-the end of the heating re el-hat 'that it-can -onl heremoved frog 1, Ab /m5 ceptacle with 1 and re-- refer to work somewhatoperation in-aTrela-Z girinding, whereas, if of the lesser depth atcated, it may be. removed in an entirely friable condition. Caremust'also betaken to heat, the pan equally throughout and to restrict theamount of water present as far as possible, so as to lessen the tendencyv forthe mass to agdglomerat'e or ball up.-

The impregnate tion (more or less complete) of fine powder,-

pumice,- which now has a coating of nlckel oxid, and 1S 1I1'&condidepending upon the care with which the heating operation has beencarried on, is then sifted into a reduction tube, which ispreferably ofthe type sho'wn inthedrawing, and 1S subjected therein to heat, while,at the same'time, a gentle current-0f hydro gen gas is allowed toact-upon the owdered mass,'thus exerting a reducin e ect upon:

- the okid, which. still firmly a heres to the pumice owder. Thehydrogen gas is preferably eectrolytic hydrogen, that is.to say,

hydrogen produce'd'from the electrol sis'of water, the water beingpreferably distilled so that the hydrogen may as pure as'possible.

coating of nickel oxid is black that is tosay, it is thecolor of blackoxid of nickel, Ni O When first introduced into the the As the reactionproceeds, the color changes -to reen, in;.th e upper layers, which ispro ably .due to .the transference of a, part of the oxygen from thepartially reduced, f

Ni O and the consequent-formation temrarily ofxthe' green ox id NiO. Finally,

owever, if the reducing operation is interru ted at'the proper time, theentire mass 'wi 1 be converted into ,nickel black. time for..interrupting the reduction-can be determined, for instance, by intetion, and noting" that moisture is deposited uponthe plate, whichthereby indicates that complete reduction. has not yet. occurred. Theskilled operator "will, after a few trials,

'. outgolng gases" near the end fofthe. which would correspond tocomplete reducbe able to determine the exact point at [which thereduction should .be interru ted in forder to obtain thenickeljblackfuner the particular conditions of temperature,

pressure, size, of apparatus, and the like,

{underfwhich heis ,o p

mind that the finalproductshouldjbe' b ck or p 'deratingly .black, incontradistinc- 4 tionto fy.

'Re m g ,trate .aconvenient apparatus for the pro peratin-g, bearin inMa- "drawings, whi h ma;

duction of the -ca talyst, the main body por-/ tion. a ofth'e reductiontube thereinshown- .may conveniently consist of a wrought ironspace forthe hy may be admitted thro h drogen gas, which latter an piped, as

-.-hav1ng at Iowerend, a. screw cap the receptionofa bod c of loose es-1 'bestos or the like, constituting a difiusion vent the powderedmaterial from sifting through into the diffusion space and clogging it.up.

At its upper end, the reduction tube is provided with a screw cap ithrough which the gas inlet tube at is admitted and whichmay be suitablyconnected to the source of hydrogen supply, as, for instance, by the 7coupling elbow shown. The screw cap 71 is provided with a screw-threadedbushing j which is removable for the purpose of filling the tube. Thebushing y' is itself provided with a screw-threaded aperture ,withinwhich fits the screw-threaded end of a tube.

70 containing a perforated screen Z and'having a filling m of looseasbestos. The upper end of the tube 70 is likewise screw-threaded orotherwise adapted to be connected to a a suitable source of collectionfor the gas is: suing from the reduction tube, the purpose of the looseasbestos filling m being to filter from the outgoing gases any dustwhich they .Illlght otherwise carry, and to prevent .any sudden blowingout of any portion of the fine material should the gas pressure, for anyreason, suddenly increase within the tube.

In practice, I find it desirable, for the successful use of reductiontubes of this'kind, to first fill them, practically to the top, with aseries of bodies of such a character aswill prevent packing of thepulverulent material and which will prevent channeling of the massduring the passage of the, gas. To this end, I have found it.advantageous to employ a filling of small rolls or cylinders n of ironwire screen material, of about'fiyscreen mesh, and which-for a pipe a ofeight inches diameter, may conveniently be of say one inch diameter andfour inches in length. When the reduction tube is filled with theserolls or cylinders n, so that there is continuous contact from top tobottom, they serve not only as a means for assisting the flow of the gasand of the water vapor or steam incident to the reduction of the nickeloxid, but also serve to transmit the heat throughout the mass and tomore fully equalize its distribution, to the general ad- 60 vantage ofthe operation.

7 As indicated in F'gs. 2 and 3, the reduc- ,tion tubes may convenientlybe heated by inserting them within a suitable heating furnace. In orderthat any particular one of thetubes may be readily withdrawn fromintervening layer of asbestos likewise prethe furnace, if necessary,without disturbing the heating of the remainder, it is found suitable tolocate them within an interior box or chamber 19 of iron or of firebrick, which box or chamber is heated externally by products ofcombustion from any suitable source, admitted at an inlet 1" into a flue8' which encompasses the inner compartment p and which has an exit at t,as indicated.

It may be said, however,'that if the tubes are properly protectedagainst radiation, and are heated at one point (say the bottom portion)to a sufficient initial heat to begin the reaction between the hydrogenand the nickel oxid (which initial heat will be in the neighborhood of500 F the chemical heat of reaction developed is propagated throughoutthe mass and is suflicient to maintain the reducing operation withoutre, lying upon the supply of additional heat 8: from the furnacegases.In fact, if the reaction is well started'inthe reduction tubes, it isfeasible to entirely out off the supply of heating gases to the furnace,the excess heat of reaction supplying the radiation losses and thetemperature conditions in the tubes remaining such as" to permit thereduction of the nickel oxidto proceed therein to the desired point. I

I find it suitable and desirable to admit the hydrogen gas under apressure of about 10 inches of water, that is to say, under such apressure as to sufiice merely toovercome the resistance due to itspassage through the reduction tube and the contents thereof, and toissue gently at the top of the asbestosfilled tube In, and, if desired,the hydrogen, as it issues from the tubes is may be ignitedthereat, soas to avoid any possibility of the formation of an explosive mixturewith the, air of the room in which the apparatus is contained. It will,of course, be understood that in making the test for moisture,hereinbefore referred to, the flame of any such burning hydrogen wouldfirst be extin guished. 1

After the nickel oxid has been sufficiently reduced, the catalyst massis cooled in a current of hydrogen until the tubes are cool enough tohandle, whereupon they are'sealed by applying a suitable screw-threadedcap to the screw-threaded upper end of the dust filter tube 70. They arethen allowed to stand until absolutely cold, whereupon when needed foruse, they are emptied, and the pulverulent vcatalyst made up of the(finely divided particles of pumice with their peripheral coating ofnickel black, is screened out from the mass'of rolls or cylinders n, andis found to be non-pyrophoric, and otherwise fully available for thepurposes for which it is intended. r

7 So far as I amaware, 't is broadly new to obtain nickel in the form ofcatalytically active'nickel black, whether deposited upon lytic materialto an ,mert carrier, therefor which comprises pulverizing to a'granular.

:mass ,the' substance which is to serve as the inert carrier, mixingthesaid mass with. hot nitrate of nickel to vcoat the. individual Y 1-. Themethod a carrier such. as powdered pumice, or otherwise. It willtherefore be understood that I intend to claim the substance broadly.

Havin I thus described my "invention,

what I c aim is:

' catalytic material on an inert carrier therefor which comprisespulverizing to a granular mass the substance which is to serve as theinert carrier, mixing with the said-mass 'an adherent material capableof conversion to a catalytic condition to "coat the indiv1d v ual grainswith said adherent material and then converting the coating thus. formedtoa catalytic; condition; substantially as de scribed.

, 2.- The method of applyin" catalytic ma-.

7 terial' to an inert carrier '-t erefor which comprises pulveri zinginto a granular mass inert carrier, mixing said mass with a reduciblemetallic salt to coat the indivl'dual gra ns thereof with the said salt,and then a converting the coating thus formed into a the substance whichis tobe used as the catalyitic state; substantially as'described.

. 3. he method of applying a coat of catalytic material to an inertcarrier therefor which comprises pulverizing into a granular massthe'substance which is to be used as' the carrier, mixing saidfmasswith. a re ducible metallic'salt to coat the individual grains thereofwith the said salt and converting the coating thus formed into an' oxid;substantially as described. 7 v 4. The methodj-of applying a coat orcatagrains thereof and then converting the coatjingflthus farmed to acatalytic condition by.

I first changing it. to nickel oxid by heat and then reducing the oxidby hydrogen; sub-;

stantially as described-J The method of -producing a catal st,.- whichcomprises coating the 'indivi ual grains' ofa ma's'sof powdered materialwith.

; aI-reducible .inetalli'c salt, converting the salt-into anoxid-under--conditions-- that will maintain the 'mass readily-i friable,and reducmg the end to the degree-required for the I desired catalyst;substantially as described.

.' {nickel oxid and .l,6;,-The method "of produc ng a catalyst,

55. upon} ow ered m'alterial fromfla slightly 7 v acidsoution ofnickel-nitrate, thereby cau'sing' the solution-to minutely'indent orrecess the individualparticles ,'of; the powdered mae o nvertn qthejmtkel nitrate into. nally: subjecting. the nickel which-coinriseslsdepositing nickel nitrate oxid to the. reducin action of,hydrogen until the desired cata yet is obtained; sub'stan' qgat el yas sbe jof forming a coating of catalyst is obtained; substantially as de--'scribed.

' drogen, in the presence of heat conducting oxid to the reducing actionof 1 hydrogen, .and interrupting the reduction in its nal .f that ispredominatingly black, and cooling the resu "gen; substantlally asdescribed.

'12. The. method of preparing a catalys tof producea compoundjin whichthe nickel is contained 7. The method of producing a catalyst whichcomprisesdepositin'g upon powder I material -a hot solution of nickelnitrate of Y such supersaturation that when 0001- it will adhere to saidparticles in the formof' solidi crystallized nickel nitrate; convertingthe nickel nitrate into nickel oxid, and subseuently subjectin thenickel oxid to the reucing action of ydrogen until the desired 8. Themethod of producing a catalyst, which comprises depositing upon theindi-' vidual grainsof'powdered material'a coat ing. of nickel nitrate,in crystallized form, spreading 'out the coated particlesin; a shalg.low layer and gently heating the same thereby converting .the nickelnitrate into nickel oxid, and subsequently subjecting the-nickel oxid tothe reducing action of hydro en until the desired catalyst is lobtaine;.substantially as described. 1

9. The method of producing a catalyst, which comprises coating powderedmaterial oxid coating to the reducing action of hy..-'

material interspersed throughout the mass, until the desired catalyst isproduced; substantially as described. t 1

- 10. The method. of producing [a nickel catalyst, which comprisessubjecting nickel oxid to the reducing action of hydrogen, and jinterrupting the reduction in its final stages before complete reductionand with the obtainin of an activecatalytic material that"catalyst,-which comprises subjecting nickel stages before.completereduction and with. theobtaining of an active catalytic materialting product in a current of hydro-;

v is pre ominatingly black; substantially as 'described.- I

11'. The methodof producing a nickel J consisting in subjecting ,a highpxid of nickel toithe reducingaction 'of'hydrogen mainly as one or moresuboxids. 'K l 13.A catalyst, comprising catalytically active nickelblack.-

14 A catalyst, comprisin catalytically 1120 upon a powactive nickelblack deposite dered material. Y a In s imony whereof. I afli'xj mysignaturein presence of two witnesses. I a JAMES BOYCE;

'. JNo. v

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